JPS5944730B2 - pressure switch - Google Patents

Description

[Detailed Description of the Invention] The present invention is a wide pressure range switch that performs opening or closing operations in a low pressure range and a high pressure range sandwiching an intermediate pressure range, which are different from those in the intermediate pressure range. This relates to a pressure switch that has been made possible.

For example, in a refrigeration system such as a car cooler, the high-pressure side pressure of the refrigerant is 7 to 15 kg/cra under normal operating conditions, but if this pressure rises abnormally, there is a danger of explosion, etc. A high voltage cutoff switch is installed to prevent this.

Additionally, in order to detect refrigerant leaks, a refrigerant leak alarm switch that is activated when the refrigerant pressure drops below a predetermined value is provided in addition to the above-mentioned high-pressure cutoff switch, and is adapted to each purpose. .

As in the above example, the present invention operates in the same way even when the fluid pressure deviates from the normal pressure range and increases excessively, or decreases excessively, and opens the contact unlike the normal state. The present invention provides a pressure switch that closes or closes the pressure switch, so that a single switch can achieve the purpose for which conventionally two pressure switches were used, and contribute to simplifying equipment and reducing manufacturing costs.

The present invention will be explained below based on illustrated embodiments.

FIG. 1 shows a first embodiment of the pressure switch of the present invention, in which the switch body C is stacked on top of the metal housing 21 and the periphery is joined to the metal housing by caulking or the like. The metal housing 21 is provided with an inlet 22 for fluid, and inside the housing 21 is a bellows 11 that receives the fluid from the inlet 22.
is provided with one end circumferential surface on the fluid inlet side airtightly fixed to the inner wall of the casing, and the free end surface of the bellows 11 has a central screw hole 1.
A bellows receiving fitting 10 having a diameter of 0a is fixed.

Bellows 11 and bellows holder 1 are on the outside of the bellows.
The metal cover 20 covering the inner bottom surface 21 of the housing 21
a, and the bellows free end surface and cover 20
A first coil spring 9 is interposed between the upper side 20b and the upper side 20b.

(The coil spring 9 can also be omitted by utilizing the spring properties of the bellows 11 or the first leaf spring 7, which will be described later.

) A second coil spring 19 having a higher elasticity than the coil spring 9 is interposed between the spring receiver 18 whose peripheral surface is fixed to the inner surface of the casing 21 and the bent bottom side 20a of the cover 20. .

The adjustment shaft 8 is located in the center screw hole 10a of the bellows holder 10.
are screwed together, pass through the upper side 20b of the cover, protrude into the insulator housing 17, and furthermore, the tip thereof is fitted into a first leaf spring 7, which will be described later, and the pressure-responsive part as described above is connected to the metal. It is configured inside the casing.

The insulator housing 17 is provided with terminals 1 and 12 that penetrate the top plate 17a and protrude outward, and are connected to an external alarm circuit.

Inside the housing 17, there is a movable contact 1 at the tip connected to the terminal 1.
4, a contact plate 2 with a quick reversal spring 3, and a terminal 12
A fixed contact 13 is connected to the movable contact 14 and moves into and out of contact with the movable contact 14, and a forced off plate 15 that hangs downward from the tip of the contact plate 2 is fitted and engaged with the tip of a second leaf spring 16, which will be described later. It has a long hole 15a and is installed vertically.

Further, an adjustment plate 4a that limits the reversal position of the movable contact 14 and adjusts the on-off difference is fixed to an adjustment screw 4 screwed into the housing upper plate 17a, and is provided to be movable up and down.

The first leaf spring 7 has one end fixed to the housing 17 together with the contact plate 2, hangs down, and is bent at a substantially right angle in the middle.
The adjustment shaft 8 is fixed to the first leaf spring 7 at a portion 7a that is inserted into the bent portion (and flattens one end of the second leaf spring 16 at the bent portion), and the leaf spring 16 is fixed to the first leaf spring 7. It is attached almost parallel to the spring 7 with an interval, and its tip is connected to the forced off plate 1 as described above.
It fits into the elongated hole 15a of No.5.

A connecting plate 5 is provided between the first leaf spring 7 and the contact plate 2, and the ends thereof are fitted and engaged with each plate, and the first leaf spring 7 and the second leaf spring 16 An adjustment screw 6 for adjusting the distance between the two leaf springs is screwed between the two leaf springs, and the above-mentioned switch section is constructed within the insulator casing.

With the above configuration, the present invention will now be described in detail.

1 to 3 show cross-sectional views of the first embodiment, and FIG. 1 shows a state where the fluid pressure inside the bellows 11 is zero or lower than a predetermined pressure, and the bellows 11 shows a length corresponding to the internal pressure. ,
The bellows receiving fitting 10 and the upper side of the cover 20 are separated from each other and have a gap α.

The adjustment shaft 8 occupies a lowered position, does not apply any pressure to the spring plate 7 and the contact plate 2, and the tip of the spring plate 16 engages with the lower end of the elongated hole 15a of the forced-off plate 15, and the movable contact 14 is pulled downward to open the connection with the fixed contact 13, and in contact with the on/off adjustment plate 4a, the alarm circuit connected to both terminals 1 and 12 is forcibly opened. It is shown that.

Next, when pressure fluid is introduced into the bellows 11 from the inlet 22, the bellows gradually expands and compresses the first coil spring 9, to the point where the upper end of the bellows receiver 10 abuts the upper side 20b of the cover 20. Stop at.

This aspect is shown by the line 1--2 in the bellows operation diagram in FIG.

FIG. 2 shows the switch in the ON pressure point state between 0 and 0 in FIG. When engaged, the leaf spring 7 is moved upward, and at the same time, the leaf spring 16 is raised, and the engagement between the leaf spring 16 and the forced off plate 15 is released.
The movable contact 14 is released from the downward pulling force and the contact plate 2
The resilient force causes the movable contact 14 and the fixed contact 13 to connect, and the alarm circuit is closed.

When the pressure of the inflowing fluid further increases, the bellows holder 1
After the cover 20 contacts the bellows, the fluid pressure opposes the second spring 19, and the extension of the bellows does not change until the fluid pressure overcomes the stored force of the spring 19.

This mode is shown by (1) to (2) in FIG. 4, and the state of the alarm circuit closed in FIG. 2 continues during the pressures (1) to (2) in FIG. 4.

When the increased fluid pressure overcomes the resiliency of the second spring 19, it compresses the spring 19 and releases the cover 20 as shown in FIG.
The bellows 11 extends so that the bottom surface 20a of the bellows 11 is separated from the bottom surface 21a of the casing, as shown in FIGS.

Accordingly, the adjustment shaft 8 bends the leaf spring 7 upward about the fixed point 7a, and further presses the contact plate 2 with the connecting plate 5, and reverses the movable contact 14 with the rapid reversal spring 3. The connection with the fixed contact 13 is released to open the alarm circuit.

In this case, the pressure value for reversing the movable contact 14 is
The projection length of the adjusting shaft 8 is set by adjusting the screw engagement between the center hole 10a of the bellows receiving fitting 10 by rotating the insulator housing 17.

When the fluid pressure decreases from the state shown in FIG.
The bellows contracts to a position where it is in balance with the elasticity of When the elasticity becomes less than , the movable contact 14 reverses again and connects with the fixed contact 14, closing the alarm circuit.

This adjustment is performed by adjusting the contact gap by moving up and down the position of the adjustment plate 4a that adjusts the on-off difference, but if the on-off difference is kept constant, this adjustment device becomes unnecessary, so it is difficult to carry out the adjustment. An example is shown in FIG. 7, which will be described later.

The fluid pressure further decreases, and at the pressure shown in Figure 4 ■, the cover 2
The bottom surface 20a of 0 comes into contact with the bottom surface 21a inside the casing, but the fluid pressure is lower than the elasticity of the first spring 9, and the coil spring 9 continues to be compressed until the pressure shown in FIG. However, the state in which the movable contact 14 and the fixed contact 13 shown in FIG. 2 continue to be connected.

When the pressure decreases below the pressure indicated by ■ in Fig. 4, the first spring 9
The elasticity of the leaf spring 16 prevails, the bellows 11 contracts, and the adjustment shaft 8 also descends, and the leaf spring 7 and leaf spring 16 also descend accordingly, and at the off setting pressure point, the tip of the leaf spring 16 reaches the length of the forced off plate 15. The forced off plate 1 engages with the bottom of the hole 15a.
5 is pulled down, the movable contact 14 connected thereto is forcibly separated from the fixed contact 13, and the alarm circuit is opened in the state shown in FIG. 1.

In this case, the pressure value when the leaf spring 16 engages or releases the engagement with the forced-off plate 15 is set by rotating the adjustment screw 6 and adjusting the tip of the leaf spring 16 up and down. It is something to do.

FIG. 5 shows another second embodiment, and FIGS.
The same parts as those in the figure are indicated by the same reference numerals, and the contact plate 20 is reversed in the opposite direction to that in the first embodiment.

The reversing spring 33 is biased upward about the fixed point C, and the movable contact plate 2 is biased downward about the fixed point 36 with the terminal 1, which is connected to the terminal 12 and fixed contact 1.
The forced off plate 15 to which the movable contact plate 2 and the forced off plate 150 are fixed is biased upward about the fixed point 37 of the terminal 12, and has a stopper 35 that limits the movement of both the movable contact plate 2 and the forced off plate 150.

Below the predetermined pressure between 0 and 0 in Fig. 4, the forced off plate 15
engages with the leaf spring 16 and forcibly separates the fixed contact 13 from the movable contact 14 to open the alarm circuit, and in the range from ■ to ■ in Fig. 4, the force-off plate 15 and the leaf spring 16 are disengaged. , connecting the movable contact 14 and the fixed contact to close the alarm circuit is the same as in Fig. 1, but in the pressure range of Fig. 4 - ■, the contact plate 2 is moved upward by the connecting plate 5. , reversal spring 33
By reducing the pressing force of the contact plate 2 against the reversing spring 33
The elasticity of the contact plate 2 is reversed upward in the figure, and the movable contact 14
is separated from the fixed contact 13.

FIG. 6 shows still another third embodiment. In the embodiment of FIG. 5, a relay contact 40 is used between the movable contact 14 and the fixed contact 13, and three contacts 13, 40, The alarm circuit is closed only when 14 is connected, and as shown in Fig. 4 ■
At the high pressure range off set pressure of ~■, the contact 14 and the relay contact 40 are separated, and at the low pressure range off set pressure of the same ~■, the contact 13 and the relay contact 40 are forcibly separated to open the alarm circuit. This is what I did.

FIG. 7 shows a fourth embodiment, in which the contacts are turned on and off as described above.
This figure shows a switch that keeps the off difference constant and eliminates the need for an on/off difference adjusting device (adjusting screw 4 adjusting plate 4a).

In the embodiments described above, the contacts close in the intermediate pressure range and the contacts open in the high and low pressure ranges, but this embodiment is a refrigeration system, and on the high-pressure discharge side of the refrigerant, It is used as a high-pressure cutoff switch that detects abnormally high discharge pressure during operation and shuts off the compressor operating circuit.When the operation is stopped, it detects a pressure drop when there is a refrigerant leak and sets a predetermined pressure value (for example, 2 kg/cri). ), it is also used as a refrigerant leak detection switch that prevents the compressor from starting.
This switch can be used for two purposes and can be suitably applied to refrigeration equipment.

Contrary to the embodiment, this switch can easily be configured to open the contact in the intermediate pressure range and close the contact in the high or low pressure range on both sides by changing the vertical position of the fixed contact with respect to the movable contact. .

As explained above, the present invention can be used in a wide range of pressures, with an intermediate pressure range in between, and in the low pressure range and high pressure range, the contacts are opened or closed, unlike in the case of the intermediate pressure range. Conventionally, separate switches were used for the high pressure range or the low pressure range,
In contrast to the conventional switch, which was designed to serve each purpose, one switch can achieve both purposes, contributing to equipment simplification and manufacturing cost savings. The bellows does not expand and contract in the middle pressure range, but expands and contracts only in the upper and lower high pressure ranges and low pressure ranges, so the pressure responsive body is small during expansion and contraction, and therefore the pressure responsive body has superior durability and a long life switch. It also has the advantage of being able to

[Brief explanation of the drawing]

Figures 1 to 3 show cross-sectional views of the first embodiment of the present invention. Figure 1 shows the switch-off mode at low pressure, Figure 2 shows the switch-on mode, and Figure 3 shows the switch at high pressure. Shows off state. FIG. 4 is a diagram showing bellows displacement with respect to pressure changes, and FIGS. 5, 6, and 7 are sectional views of other embodiments. 1.12...terminal, 2...contact plate, 3
...Reversal spring, 4...On/off difference adjustment screw, 5...Connection plate, 6...Adjustment screw, 7...1st Leaf spring, 8...adjustment shaft,
9...First coil spring, 10...Bracket, 11...Pressure responsive body (bellows), 13.
...Fixed contact, 14...Movable contact, 15
... Forced off plate, 16 ... Second plate spring, 17 ... Insulator casing, 18 ... Fixed spring holder, 19 ... ...Second coil spring, 20...
...Cover, 21...Metal casing, 22...
...Inlet.

Claims (1)

[Scope of Claims] 1. In a switch body in which an insulator casing is stacked and combined on a metal casing, a pot-shaped tip is provided with the periphery of the opening placed on the bottom surface of the metal casing. A pressure-responsive body whose opening periphery is airtightly fixed to the bottom surface of the casing and a pressure fluid is introduced into the cover, and a receiving metal fitting fixed to the free end surface of the pressure-responsive body and having a central screw hole. a first spring that accommodates the spring, is screwed into the center screw hole, and is provided with an adjustment shaft that protrudes outwardly through the upper side of the cover so as to be vertically adjustable, and counteracts the low pressure range of the pressure responsive body; A second spring is provided, one end of which is fixed to the housing and the other end of which is placed on the periphery of the cover, to counter the pressure in the intermediate and high pressure ranges of the pressure responsive body, and Then, the pressure-responsive body expands and contracts in opposition to the first spring until the receiving fitting still contacts the cover, and after the receiving fitting contacts the cover, in the intermediate pressure range, the first spring contracts while applying a counter pressure. The elasticity of the first and second springs is set so that the responsive body does not displace but opposes the second spring, and in a high pressure range, the second spring is compressed and the pressure responsive body expands and contracts. A pressure-responsive part configured to transmit the movement of the pressure-responsive body due to a pressure change to the adjustment shaft, a first plate spring into which the adjustment shaft is fitted and engaged when the adjustment shaft rises, and the operation of the plate spring is connected. A contact plate having a movable contact that is transmitted through the plate, a fixed contact that comes into contact with and separates from the movable contact, and an adjustment device that sets the pressure in a high pressure range that releases or connects the movable contact and the fixed contact. A pressure switch comprising: a switch portion comprising: and an adjusting device for forcibly releasing the connection between the fixed contact and the movable contact or setting a pressure in a low pressure range for connecting the fixed contact and the movable contact. 2. In the pressure switch according to claim 1, the adjustment shaft is rotated by rotating the insulator casing, and the protrusion length of the adjustment shaft is adjusted to connect the fixed contact and the movable contact. A regulating device that sets the pressure of a high pressure range to be released or connected. 3. In the pressure switch according to claim 1, one end of the first leaf spring is fixed to the first leaf spring, and the first leaf spring is substantially parallel to the first leaf spring at a distance from the first leaf spring. A second leaf spring is provided above the leaf spring, and an adjustment screw is provided to adjust the distance between the first leaf spring and the second leaf spring, and the tip of the second leaf spring is adjusted up and down. By inserting the tip of the second leaf spring into the elongated hole of the forced-off plate connected to the movable contact of the contact plate and installed vertically, the second leaf spring engages with the bottom of the elongated hole and is forced off. setting a pressure in a low pressure range that automatically releases the connection between the fixed contact and the movable contact, or a pressure in the low pressure range that disengages the engagement between the second leaf spring and the forced off plate and connects the movable contact and the fixed contact. Regulator to set pressure.